Private Instance Methods

requirements is a list of version requirements that the
specified gem must match, most commonly "= example.version.number". See Gem::Requirement for how to specify a
version requirement.

If you will be activating the latest version of a gem, there is no need to
call #gem, Kernel#require will do
the right thing for you.

#gem returns true if the gem was
activated, otherwise false. If the gem could not be found, didn't match
the version requirements, or a different version was already activated, an
exception will be raised.

#gem should be called
before any require statements (otherwise RubyGems may load
a conflicting library version).

In older RubyGems versions, the environment variable GEM_SKIP could be used
to skip activation of specified gems, for example to test out changes that
haven’t been installed yet. Now RubyGems defers to -I and the RUBYLIB
environment variable to skip activation of a gem.